I agree with Coding badly.
A board which is functionally either the same or similar to a given Arduino board, and claims compatibility is legitimate but one which aims to look like an Arduino board without not being made by Arduino is clearly a fake.
Another way to look at it is this:
Manufacturer A makes an Arduino compatible board, they are proud of their work, and they put their name on it.
Manufacturer B claims their boards are made thousands of miles away by manufacturer Z.
Who do you trust to buy a board from?